Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > General > Audio encoding

Reply
 
Thread Tools Search this Thread Display Modes
Old 3rd July 2009, 22:24   #1  |  Link
MrC
AVStoDVD Dev
 
MrC's Avatar
 
Join Date: Apr 2006
Location: Italy
Posts: 1,302
5.1 formats to 5.1 AC3

Dealing with 6 channels audio conversions, what are the correct channels mappings (using AviSynth's GetChannel) for following formats?

5.1 AC3 -> 5.1 AC3 ... should be GetChannel(1,3,2,5,6,4)
5.1 AAC -> 5.1 AC3
5.1 DTS -> 5.1 AC3
5.1 WAV -> 5.1 AC3

Thanks in advance!



Bye
__________________
MrC

AVStoDVD Homepage
AVStoDVD @ Doom9 Forum
MrC is offline   Reply With Quote
Old 3rd July 2009, 23:27   #2  |  Link
Kurtnoise
Swallowed in the Sea
 
Kurtnoise's Avatar
 
Join Date: Oct 2002
Location: Aix-en-Provence, France
Posts: 5,194
http://avisynth.org/mediawiki/GetChannel or from the Avisynth doc...
Kurtnoise is offline   Reply With Quote
Old 3rd July 2009, 23:51   #3  |  Link
tebasuna51
Moderator
 
tebasuna51's Avatar
 
Join Date: Feb 2005
Location: Spain
Posts: 6,125
Quote:
Originally Posted by MrC View Post
Dealing with 6 channels audio conversions, what are the correct channels mappings (using AviSynth's GetChannel) for following formats?

5.1 AC3 -> 5.1 AC3 ... should be GetChannel(1,3,2,5,6,4)
5.1 AAC -> 5.1 AC3
5.1 DTS -> 5.1 AC3
5.1 WAV -> 5.1 AC3
I can't understand your question.
The order inside AviSynth is always FL,FR,FC,LF,BL,BR

The audio decoders NicAudio, BassAudio, DirectShowSource always suply the uncompressed audio in that order.

And AviSynth must suply uncompressed audio in that order to compliant encoders like Aften or NeroAacEnc (DTS encoders need mono wav's)

The internal channel order in compressed formats can be ignored by the users and only must be know by decoders/encoders
__________________
BeHappy, AviSynth audio transcoder.
tebasuna51 is offline   Reply With Quote
Old 4th July 2009, 00:05   #4  |  Link
Kurtnoise
Swallowed in the Sea
 
Kurtnoise's Avatar
 
Join Date: Oct 2002
Location: Aix-en-Provence, France
Posts: 5,194
I think he wants to know the correct channels orders to use Aften with different sources...
Kurtnoise is offline   Reply With Quote
Old 4th July 2009, 01:56   #5  |  Link
Brazil2
Registered User
 
Join Date: Jul 2008
Posts: 487
Quote:
Originally Posted by MrC View Post
5.1 AAC -> 5.1 AC3
Take care because AFAIK channel order for AAC 5.1 is C, L, R, SL, SR, LFE.
Brazil2 is offline   Reply With Quote
Old 4th July 2009, 02:50   #6  |  Link
tebasuna51
Moderator
 
tebasuna51's Avatar
 
Join Date: Feb 2005
Location: Spain
Posts: 6,125
Quote:
Originally Posted by Kurtnoise View Post
I think he wants to know the correct channels orders to use Aften with different sources...
But inside AviSynth don't exist different sources, is always uncompressed audio with the same channel order.

And also out of AviSynth you can use Faad (aac decoder) and Aften without remapping:

faad -w input.aac | aften -readtoeof 1 - output.ac3

Only broken decoders output uncompressed audio with the internal channel order. Do you know any?
__________________
BeHappy, AviSynth audio transcoder.
tebasuna51 is offline   Reply With Quote
Old 4th July 2009, 20:44   #7  |  Link
MrC
AVStoDVD Dev
 
MrC's Avatar
 
Join Date: Apr 2006
Location: Italy
Posts: 1,302
Ok, more info about the whole scenario.

- The encoders are Wavi+Aften
- The input file is a very simple avs script that point to a audio file (ac3/aac/dts/wav) thru DSS and GetChannel.

AC3
Code:
GetChannel(DirectShowSource(InputAudio),1,3,2,5,6,4)
It matches with AviSynth doc and it works.

AAC
Code:
GetChannel(DirectShowSource(InputAudio),2,1,3,4,5,6)
It does not match with AviSynth doc but it works. Thanks Brazil2.

DTS
Code:
GetChannel(DirectShowSource(InputAudio),3,1,2,5,6,4)
Assuming that AviSynth doc is correct, it should be like that.

WAV
Code:
GetChannel(DirectShowSource(InputAudio),1,2,3,4,5,6)
Assuming that AviSynth doc is correct, it should be like that.

What do you think?

Bye
__________________
MrC

AVStoDVD Homepage
AVStoDVD @ Doom9 Forum
MrC is offline   Reply With Quote
Old 4th July 2009, 22:40   #8  |  Link
tebasuna51
Moderator
 
tebasuna51's Avatar
 
Join Date: Feb 2005
Location: Spain
Posts: 6,125
Quote:
Originally Posted by MrC View Post
What do you think?
I don't know for what you ask if you don't read the answers.

All is wrong, except WAV of course.
__________________
BeHappy, AviSynth audio transcoder.
tebasuna51 is offline   Reply With Quote
Old 5th July 2009, 12:43   #9  |  Link
MrC
AVStoDVD Dev
 
MrC's Avatar
 
Join Date: Apr 2006
Location: Italy
Posts: 1,302
Quote:
Originally Posted by tebasuna51 View Post
All is wrong, except WAV of course.
Really? If my ears do not fail, AC3->AC3 and AAC->AC3 using those settings and the listed software (AviSynth, Wavi and Aften) are correct.



Bye
__________________
MrC

AVStoDVD Homepage
AVStoDVD @ Doom9 Forum
MrC is offline   Reply With Quote
Old 5th July 2009, 18:34   #10  |  Link
tebasuna51
Moderator
 
tebasuna51's Avatar
 
Join Date: Feb 2005
Location: Spain
Posts: 6,125
Try with a channel test like http://www-mmsp.ece.mcgill.ca/Docume...Channel_ID.wav
__________________
BeHappy, AviSynth audio transcoder.
tebasuna51 is offline   Reply With Quote
Old 5th July 2009, 20:26   #11  |  Link
MrC
AVStoDVD Dev
 
MrC's Avatar
 
Join Date: Apr 2006
Location: Italy
Posts: 1,302


I will make some tests and will post the results



Bye
__________________
MrC

AVStoDVD Homepage
AVStoDVD @ Doom9 Forum
MrC is offline   Reply With Quote
Old 6th July 2009, 22:27   #12  |  Link
MrC
AVStoDVD Dev
 
MrC's Avatar
 
Join Date: Apr 2006
Location: Italy
Posts: 1,302
I made some tests and, tebasuna51, you are absolutely right: using a valid AC3 encoder (Aften) there is no need to remap channels, whatever source format. Instead using a *not so good* AC3 encoder, QuEnc, I found that remapping is necessary (1,3,2,5,6,4).

I apologize for having spread my wrong assumptions, but I really found a lot of confusing stuff about this item around the web.



Bye
__________________
MrC

AVStoDVD Homepage
AVStoDVD @ Doom9 Forum
MrC is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 06:07.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.